Fair Value Measurements - Reconciliation of Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Balance, beginning of period	$ 1,673	$ 1,065
Included in earnings	(67)	122
Purchases/originations	30	184
Settlements	24	12
Transfers into Level 3	4	6
Balance, end of period	1,664	1,389
The amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held	(56)	197
Derivative assets	2,750		$ 3,171
Derivative liabilities	3,300		$ 3,951
Unrealized gains or losses included in other comprehensive income for instruments still held	0	0
Interest rate contracts | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Derivative assets	11	8
Derivative liabilities	8	10
Servicing Rights
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Balance, beginning of period	1,746	1,121
Included in earnings	(53)	137
Purchases/originations	32	186
Settlements	0	0
Transfers into Level 3	0	0
Balance, end of period	1,725	1,444
The amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held	(35)	207
Interest rate contracts
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Balance, beginning of period	(1)	4
Included in earnings	14	2
Purchases/originations	(2)	(2)
Settlements	(8)	(6)
Transfers into Level 3	0	0
Balance, end of period	3	(2)
The amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held	7	7
Equity Derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Balance, beginning of period	(195)	(214)
Included in earnings	(31)	(11)
Purchases/originations	0	0
Settlements	34	27
Transfers into Level 3	0	0
Balance, end of period	(192)	(198)
The amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held	(31)	(11)
Residential Mortgage Loans
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Balance, beginning of period	123	154
Included in earnings	3	(6)
Purchases/originations	0	0
Settlements	(2)	(9)
Transfers into Level 3	4	6
Balance, end of period	128	145
The amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held	$ 3	$ (6)